Friction shock absorbing mechanism



June 20, 1933. H. F. wor-:RNLEY FRICTION SHOCK ABSORBING MECHANISM Filed April l5, 1931 v INVENTOR. HARRY EWGERN/ EY @www m A TTORN E Y.

Patented June 20, 1933 Unirse sra'rss ATE FCE 'HARRY F. WOERNLEY, OF WILKINSBURG, PENNSYLVANIA, ASSIGN'OR T0 THE WEST- INGHOUSE AIR BRAKE COMPANY, OF W'ILM' R-ATION OF PENNSYLVANIA.

FRIC'IION SHOCK .ABSORBING IlECHAN ISM Application filed April 15,

My invention relates to improvements in friction draft rigging for railway cars and more particularly to the shock absorbing mechanism of said draft rigging of the` type employing a casing containing spaced sets of alternated stationary and longitudinally movable friction elements which are forced apart by a we-dging mechanism comprising wedge shoes and front and rear w'edges cooperating with the wedge shoes.

I have found that, when a shock absorbing mechanism of the above type is being compressed under draft or buliing stresses, the several parts of the wedging mechanism do not readily accommodate themselves to the limited opening into which they are forced,

` with the result that they cause an abnormal outward pressure on the friction elements and sides of the casing, and consequently the shock absorbing mechanism is'caused to offer abnormal resistance to draft and bufling stresses.

The principal object of my invention is to provide a friction shock absorbing mechanism for railway draft rigging in which the several parts of the wedging mechanism will readily accommodate themselves to the positions to which they are moved when the mechanism is being compressed without un` duly increasing the resista-nce of the mechanisin to draft and bufling stresses.

rlhis object I accomplish by providing the shock absorbing mechanism with yieldable means which are so disposed that they may be slightly compressed when the mechanism is subjected to either bufng or draft stresses,

so as to permit the several parts of the wedgv ing mechanism to accommodate themselves to the positions to which they are moved without unduly increasing the resistance of the mechanism to bufing and draft stresses.

In the accompanying drawing; Fig. l is a longitudinal horizontal sectional view of a draft rigging embodying my invention; Fig. 2 is a detail face view of a friction element made in accordance with the invention, portions being broken away to more clearly illustrate the several parts of the element; and each of the Figs. 3, 4, 5 and Gis afragmentary 1931. Serial No. 530,163.

railway car, to the inner faces of which are 355 secured front stop lugs 2 and rear stop lugs 3.

My improved shock absorbing mechanism is interposed between the draft sills in suoli a manner that the rear end of the mechanism abuts the rear stop lugs 3 and the forward end :.60

abuts the inner face of a follower plate e', which in turn, is adapted to abut the front stop lugs 2.

The rear end of the shock absorbing mechanism is engaged by the draft yoke 5 which extends around the mechanism and which at its outer end is secured in the usual manner to the rear end 6 of the ordinary coupler, said rear end of the coupler being adapted to engage the outerr face of the follower plate 4.

The shock absorbing mechanism and 5 are supported by the usual carrier which is secured to the bottoms 0f the yoke plate 7 sills l.

may comprise a hollow rectangular casing 8 having a closed rear end which is adapted to abut the rear stop lugs 3 and which is adapted to be operatively engaged by the rear end portion of the draft an open forward end.

Contained in the open forward end of the casing are two sets of alternated stationary and movable friction elements, which sets are spaced apart by a wedging mechanism coin-f" prising wedge shoes 9 and l0, which are adapted to be spread apart by front and rear wedge blocks ll and l2.

Each set of friction elements comprises a.

stationary element 13 and a stationary clef'90 element lll and an adjacent wedge shoe.

According to one form of my invention ERDING, PENNSYLVANIA, .A CORPG- rear end portion of rif-35 yoke 5, and also havngi( and as illustrated in F ig. l of t-lie drawing,

the stationary friction element la comprises plates 17 and 18, between which there is interposed a layer or sheet 19 of slightly resilient material, which may be made from any suitable rubber composition or the like. The resilient material may be attached to either one or both of the plates 17 and 18 or may be separate from both plates.

Also contained in the casing 1 are coil springs 20, 21 and 22, the rear ends of which seat on the closed end of the casing. The outer ends of the springs 2O and 21 seat on a follower 23 which is contained in the casing and which engages with the rear edges of the movable friction elements 15 and 16 and with the rear wedge block 12.

The wedge blocks 11 and 12 have opposed wedging faces 24 and 25 respectively, which engage corresponding end wedging faces 26 and 27 of the wedge shoes. Each of the wedge shoes has an outer friction face 28 which is in frictional engagement with the adjacent movable friction eIement 16.

The wedge block 11 has a rearwardly extending stem 29 having an opening formed therein through which a locking key 30 passes, the ends of said key passing through slotted openings formed in the top and bottom walls of the casing 1 in the usual manner.

The locking key 30 is for the purpose of maintaining the several parts of the shock absorbing mechanism connected to the casing 1 under initial compression, and to lock the key against accidental movement in the direction of its length, a member 31 is provided having a. projection 32 which extends through a bore in the stem 29 into locking engagement with the key and is maintained in such engagement by the pressure of the spring 22.

The drawing shows ther shock absorbing mechanism in its expanded position, that is,

when not subjected to either bu'liing or draft stress. YWhen subjected to either of these stresses, the wedge blocks 11 and 12 force the wedge slices 9 and 10 apart, and the wedge shoes in turn force the stationary and movable frictional elements into closer engagement with each other. As the wedge shoes are thus spread apart, the resilient members 19 between the stationary plates 17 and 18 of each set of friction elements are slightly compressed, and due to this, permit the several parts of the wedge mechanism to accommodate themselves to their gradual change in position when the mechanism is being compressed without unduly increasing the outward pressure on the sets of friction elements and side walls of the casing.

In Fig. 3, a modification of my invention is illustratedin which each of the movable friction elements 16 is provided with a recess in whicha shoe 33 is loosely mounted, the outer face of which is adapted to be frictionally engagedby the friction face 28 of one of the wedge shoes, a layer Sel of rubber composition being interposed between the plate 16 and the inner face of the shoe 38.

Another modification is illustrated in Fig. 1, in which each of the wedge shoes has a recess containing a plate 35 for frictional engagement with the adjacent movable friction elements 16 and in which a layer 36 of rubber composition is interposed between the wedge shoe and plate 35.

A further modification is illustrated in Fig. 5, in which each side of the forward end portion of the wedge block 11 is provided with a recess in which there is mounted a shoe 37 which is adapted to frictionally engage the friction face 26 of the adjacent wedge shoe and in which a layer 38 of rubbei` composition is interposed between the wedge block and the shoe 37.

In Fior. 6, a still further modification is illustrated in which each of the wedge shoes lis provided with a recess containing a plate 39 for frictional engagementwith the adjacent friction face 24 of the wedge block 11 and in which a layer 10 of rubber composition is interposed between the plate 39 and wedge shoe. i

Each of the modifications above described will operate to permit the several parts of the wedging mechanism to accommodate themselves to the positions to which they are moved under bufiing and draft stresses in the same manner as described in connection with the form of the invention illustrated in Fig, 1.

It will be noted that with the yieldable members 19, 34 36, 38 and 410 interposed in the shock absorbing mechanism in the manner before described, the mechanism will offer more uniform'resistance to bufiing and draft stresses than has heretofore been possible.

Vhile several illustrative embodiments of the invention have been described in detail, it is not my intention to limit its scope to these embodiments or otherwise than by the terms of the appended claims.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a shock absorbing mechanism, the combination with a easing, of friction elements mounted in said casing and movable longitudinally relative thereto, friction elements mounted in said casing against longitudinal movement relative to the casing, wedging means operative to impress lateral pressure on said elements when the mechanism is subjected to draft and buiing stresses, means disposedbetween two of said elements at each side of the wedging means yieldable to the lateral pressure exerted by said wedging means under draft and buffng stresses, and means for releasing the shock absorbing mechanism.

2. In a shock absorbing mechanism, the combination with a casing, of alternated stationary friction elements and movable friction elements mounted in said casing, Wedging means operative to impress lateral pressure on said friction elements, means at each side of the Wedging mechanism interposed between said Wedging mechanism and each of said elements yieldable to the pressure exerted by the Wedging means, each of the interposed means comprising a laterally movable friction shoe and also comprising a member yieldably resisting lateral movement of said shoe, and means for releasing the mechanism.

3. In a shock absorbing mechanism, the combination with a casing, of alternated stationary friction elements and movable friction elements mounted in said casing, Wedging means operative to impress lateral pressure on said friction elements, means included in said vvedging means yieldable under draft and buihng stresses, said means comprising a laterally movable friction shoe disposed at each side of the Wedging means and also comprising a. member disposed at each side of the Wedge means for resisting lateral movement of the adjacent friction shoe, and means for releasing the mechanism.

4. In a friction shock absorbing mechanism, the combination With a casing, of a plurality of friction elements mounted in said casing, said elements consisting of a plurality of friction plates arranged at each side of the longitudinal center line of the casing and also consisting of Wedge members operable to impress lateral pressure on said friction plates when the shock absorbing mechanism is subjected to draft and buiiing stresses, means disposed between tvvo of said friction elements at each side of the longitudinal center line of the casing yieldable to the lateral pressure exerted by said Wedge means, said means comprising a member in slidable engagement With at least one of said friction elements and movable in a direction transversely of the center line of the casing and also comprising means yieldably resisting the transverse movement of said member, and means for releasing the mechanism.

In testimony whereof I have hereunto set my hand, this 13th day of April, 1931.

HARRY F. WOERNLEY. 

